Vacuum Cleaner Had an Unserviceable Filter

Recently our vacuum stopped working as well as it used to. Granted, we track in dirt from the garage, and have little kids and a dog running around; but the vacuum should still be able to do its job.

I started the investigation with my first gut feeling -- the belt was loose, or maybe the scrubber was jammed with hair and carpet fibers. The belt checked out fine and I removed a Persian rug's worth of thread and hair from the roller. Next, the filter was replaced and everything washed out of the bag/inlet area. Nothing worked -- the vacuum was just not pulling as hard as it did when it was new.

So, determined to not spend money on a new vacuum, I decided to go all mechanical engineer on the beast. I was suspecting loose clearances in the vacuum’s centrifugal pump area, clogged internal lines, or some sign of motor damage/overheating that could be lowering shaft RPM. What I found made me want to kick someone.

The hunt started with the removal of about 18,000 Torx screws, scattered across the seven continents of the giant extrusion known as the back of my vacuum. I only ended up breaking one tab that was sneakily hidden under the cord wrapping. I certainly drive cars that have more self-inflicted damage than that. Accessories, hoses, pivots, cup holders, all of it had to come off before I could get far enough in to find the vacuum itself.

Finally, the heart of the machine slumped out onto the bench. I worked the shaft back and forth, nothing seemed too loose or tight. No debris was filled in the chamber or inlet of the pump. I even used my air compressor to spin the pump over for a second -- no grinding or much resistance to movement at all. My problem didn’t seem to be coming from this end, and I knew the entire filter and upper hose assembly were clean.

OK, so the air can get into the vacuum without much problem -- could it be having trouble getting it out? The design seemed smart -- the outlet of the pump wraps around the motor windings to cool it with outlet air. A thin foam filter lays around that assembly and then out through openings. Then, I noticed something covering the outlet openings. It was a dense, felt-like material and was completely clogged with dirt and debris. The felt was certainly much more dense than any of the filtering elements in the system, and was about 1/16-inch thick. The pressure drop had to be pretty significant compared to the rest of the system. I started washing it, planning on putting the piece back in and seeing if my problem was solved. I got to thinking; this is only going to happen again as the dust builds up from day-to-day use. So instead, I left the felt out and reassembled the machine. It is back to acting like new and might even have a little more power now.

The moral of the story? Try not to place unserviceable filters in a device that moves lots of dirty air. In this case the “filter” was almost more of a safety element, as it kept small things (paperclips, pennies, forks) from stabbing directly into the plastic slots on the front of the vacuum and into the motor windings.

This concern could have been alleviated by designing the slots in a waffle pattern, instead of long, narrow channels. If a filter on the outlet was really necessary (as I’ve had vacuums with a HEPA filter in this location) try to make it replaceable. Of course, the whole design could very well be a wise marketing move to make this a vacuum that only works for a few years and then ends up in the trash.

Do you remember some of the older, all-metal vacuums? These were around in the day when vacuum repair was a “thing” and not just what frustrated engineers might do in their time off. Hopefully this story can help us all feel a crack on the knuckles the next time we’re thinking of hiding something that should be serviceable, deep down in a machine.

Tell us your experiences with Monkey-designed products. Send stories to Lauren Muskett for Made by Monkeys.

I'm in my twenty-ninth year of experience serving industrial clients and nothing surprises me anymore. I used to ask, "How much more stupid could they get?" and not a month passes without the trophy passing to a new recipient. To be fair it's not just Ford or even the automotive industry (though they are leading the pack) it's everything from waste shredding/compacting equipment to residential refrigerators. Brand new air conditioner, how brilliant to use a non-corrosive plastic condensate tray then attach it with steel rivets that will rot out in a couple years. How brilliant to locate the completely unnecessary and overly delicate electronic control directly above the oven vent on kitchen range where it gets blasted with steam and 500°F heat. Failure to install <$500 worth of bearing guards to prevent a $65k failure on a $1.2 million machine. Total loss of a machine and over $2 million in damages resulted from a short-circuit that would have been prevented had engineering not considered a $100 fuse assembly "unnecessary".

Now I see. You are right, of course! (I was guessing the system could pressure drive the back flow, now I see it is not the case).

And I suspect the placement above the engine could have other disadvantages too. (Air pockets?)...

I personally hate when filters are not mounted vertically with the mounting face upwards... horizontally mounted ones always tend to spill some oil on engine or on the floor. I have the practice of minimizing lack of lubrication trying to fill fliters as much as possible before screwing them to the engine block. When assembling a new or rebuilt engine, I used means to turn the oil pump in order to prelubricate the entire engine before the critical first start-up. From time to time, I found engines with some problem like one rocker arm not feeding oil, and dirt dislodged from dirty oil galleries from not properly cleaned engine blocks. But knowing that Ford designed such a filter on top of the engine only raises my disbelief on that company designs and products. Amclaussen.

What happens with the oil pan does not change the fact that the oil filter is mounted on the top of the engine. When the seal on the filter housing is broken, the backflow of oil flushes dirt/debris stopped by the filter back into the oil passages. Stirring up dirt means premature death in any lubrication system. There are two primary reasons why properly designed cartridge filter housings allow the cartridge to remain in the bowl as it's being removed: 1. All trapped materials remain in the housing; 2. the filter & housing can be pre-lfilled before installing to minimize dry-run periods.

Battar: This counter is embedded into the front door of the electrical control panel for this floor-mounted machine. I'd venture to guess that MOST often counters such as this one are mounted in similar enclosures, NOT subject to the forces of an F-16 in full rollover mode. Furthermore, you couldn't fit an extra feather into this 1/16 DIN case of the counter. The battery has welded tabs to its terminals, and these tabs are soldered into the small P.C. Board. So, even IF I wanted to unsolder the dead battery, I would not be able to source a new one to replace it that had the welded tabs already fastened. It was just a poor intial design. The replacement counter utilizes a coin cell, which IS much more practical, since I'd be willing to bet that OMRON received many complaints about the initial design. You have to realize that production-line machinery IS usually designed to last decades, not just years.

Our compamy sold a product with the same type of soldered 1/2AA lithium thionyl battery, but we have since changed the design to use non-soldered types. But there is method in the madness - first, the soldered types wouldn't bounce about and cause voltage drops if the unit was knocked or dropped (we had to design a special battery holder to get round that one), second, most of our customers know how to solder a couple of tabs to a circuit board, and third, very few, if any of our customers use, or intend to use, the same product 10 years straight.

William K. - you reminded me of the good old days when choices were limited because the focus was on quality. From http://www.hyperwrite.com/Articles/showarticleshort.aspx?id=90

One of Henry Ford's famous quotes about the Model T was, "Any customer can have a car painted any colour that he wants, so long as it is black."

The Model T only came in black because the production line required compromise so that efficiency and improved quality could be achieved. Spraying different colours would have required a break in the production line, meaning increased costs, more staff, more equipment, a more complicated process, and the risk of the wrong colour being applied.

Nancy G. I read an interesting paragraph in a blog a few weeks back, where, at the start of the paragraph the author stated that designers were attempting to satify "The consumer demand for more features", but then at the end of the paragraph the author commented that "The designers were using all of these new tools in attempting to create designs that would CAPTURE THE CONSUMERS IMAGINATION", which I see as an admission that consumer demand has not much to do with the proliferation of useless and bothersome features that so many products have. It is not about consumer demand, it is about marketers seeking that holy grail of "product differentiation" that is responsible for the drop in actual quality of many products.

@William K. I completely agree with your statement: "And as for minimizing cost, I would be happy to pay 10% more for a product that would last and could be repaired."

Unfortunately the current marketing trend is driven by the consumer response that cheaper is better and thus quality is sacrificed as manufacturers shave every penny to be cost-competitive. In that type of marketing environment we aren't even offered that option any longer because companies simply can't compete.

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